Restore MD5 hashes

This commit restores the ComputeMD5Hash() array extensions to use MD5 internally again.
Previously this has been changed to use SHA1 internally since the MD5 implementation
is not supported on all platforms.

See also:

eb88233
64dd566
b750926

src/Aardvark.Base/Extensions/ArrayExtensions.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using System.Security.Cryptography;
@@ -2336,7 +2335,7 @@ public static Span<byte> AsByteSpan<T>(this T[] data) where T : struct
         {
             return MemoryMarshal.AsBytes(data.AsSpan());
         }
-        
+
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static ReadOnlySpan<byte> AsByteSpan(this string data)
         {
@@ -2392,44 +2391,33 @@ internal static unsafe void UseAsStream(this Array data, Action<UnmanagedMemoryS
 
         #region Hashes
 
+        #region MD5
+
         /// <summary>
         /// Computes the MD5 hash of the data array.
         /// </summary>
         /// <returns>128bit/16byte data hash</returns>
         public static byte[] ComputeMD5Hash(this byte[] data)
         {
 #if NET6_0_OR_GREATER
-            var hash = SHA1.HashData(data);
-            Array.Resize(ref hash, 16);
-            return hash;
+            return MD5.HashData(data);
 #else
-            using (var sha = SHA1.Create())
-            {
-                var hash = sha.ComputeHash(data);
-                Array.Resize(ref hash, 16);
-                return hash;
-            }
+            using var md5 = MD5.Create();
+            return md5.ComputeHash(data);
 #endif
         }
-        
+
         /// <summary>
         /// Computes the MD5 hash of the data array.
         /// </summary>
         /// <returns>128bit/16byte data hash</returns>
         public static byte[] ComputeMD5Hash(this Array data)
         {
 #if NET6_0_OR_GREATER
-            var hash = SHA1.HashData(data.AsByteSpan());
-            Array.Resize(ref hash, 16);
-            return hash;
+            return MD5.HashData(data.AsByteSpan());
 #else
-
-            using(var sha = SHA1.Create())
-            {
-                var hash = data.UseAsStream((stream) => sha.ComputeHash(stream));
-                Array.Resize(ref hash, 16);
-                return hash;
-            }
+            using var md5 = MD5.Create();
+            return data.UseAsStream((stream) => md5.ComputeHash(stream));
 #endif
         }
 
@@ -2439,11 +2427,7 @@ public static byte[] ComputeMD5Hash(this Array data)
         /// </summary>
         /// <returns>128bit/16byte data hash</returns>
         public static byte[] ComputeMD5Hash<T>(this T[] data) where T : struct
-        {
-            var hash = SHA1.HashData(data.AsByteSpan());
-            Array.Resize(ref hash, 16);
-            return hash;
-        }
+            => MD5.HashData(data.AsByteSpan());
 #endif
 
         /// <summary>
@@ -2453,14 +2437,16 @@ public static byte[] ComputeMD5Hash<T>(this T[] data) where T : struct
         public static byte[] ComputeMD5Hash(this string s)
         {
 #if NET6_0_OR_GREATER
-            var hash = SHA1.HashData(s.AsByteSpan());
-            Array.Resize(ref hash, 16);
-            return hash;
+            return MD5.HashData(s.AsByteSpan());
 #else
             return Encoding.Unicode.GetBytes(s).ComputeMD5Hash();
 #endif
         }
 
+        #endregion
+
+        #region SHA1
+
         /// <summary>
         /// Computes the SHA1 hash of the data array.
         /// </summary>
@@ -2518,6 +2504,10 @@ public static byte[] ComputeSHA1Hash(this string s)
 #endif
         }
 
+        #endregion
+
+        #region SHA256
+
         /// <summary>
         /// Computes the SHA256 hash of the data array.
         /// </summary>
@@ -2575,6 +2565,10 @@ public static byte[] ComputeSHA256Hash(this string s)
 #endif
         }
 
+        #endregion
+
+        #region SHA512
+
         /// <summary>
         /// Computes the SHA512 hash of the data array.
         /// </summary>
@@ -2632,6 +2626,10 @@ public static byte[] ComputeSHA512Hash(this string s)
 #endif
         }
 
+        #endregion
+
+        #region Adler32
+
         /// <summary>
         /// Computes a checksum of the data array using the Adler-32 algorithm (<see cref="Adler32"/>).
         /// </summary>
@@ -2687,6 +2685,8 @@ public static uint ComputeAdler32Checksum(this string s)
             return a.Checksum;
         }
 
-#endregion
+        #endregion
+
+        #endregion
     }
 }

src/Aardvark.Base/Extensions/StringExtensions.cs

@@ -363,16 +363,22 @@ public static IEnumerable<string> NestedBracketSplit(this string text, int split
         #region Guid
 
         /// <summary>
-        /// Computes the MD5 hash of the given string and returns it as Guid.
+        /// Computes the SHA1 hash of the given string and returns it as Guid.
         /// </summary>
         public static Guid ToGuid(this string self)
         {
             if (string.IsNullOrEmpty(self)) return Guid.Empty;
-            return new Guid(self.ComputeMD5Hash());
+            var hash = self.ComputeSHA1Hash();
+#if NET8_0_OR_GREATER
+            return new Guid(hash.AsSpan(0, 16));
+#else
+            Array.Resize(ref hash, 16);
+            return new Guid(hash);
+#endif
         }
 
         /// <summary>
-        /// Combines the given strings and returns a Guid based on the MD5 hash.
+        /// Combines the given strings and returns a Guid based on the SHA1 hash.
         /// </summary>
         public static Guid ToGuid(this IEnumerable<string> self)
         {
@@ -382,7 +388,7 @@ public static Guid ToGuid(this IEnumerable<string> self)
         }
 
         /// <summary>
-        /// Combines the given Guids to a string and returns a Guid based on the MD5 hash.
+        /// Combines the given Guids to a string and returns a Guid based on the SHA1 hash.
         /// </summary>
         public static Guid ToGuid(this IEnumerable<Guid> self)
         {
@@ -391,7 +397,7 @@ public static Guid ToGuid(this IEnumerable<Guid> self)
             return sb.ToString().ToGuid();
         }
 
-        #endregion
+#endregion
 
         #region Properties
 

src/Aardvark.Base/Introspection/Introspection.cs

@@ -10,6 +10,7 @@
 using System.Reflection.PortableExecutable;
 using System.Runtime.InteropServices;
 using System.Runtime.Serialization;
+using System.Security.Cryptography;
 using System.Text;
 using System.Text.RegularExpressions;
 using System.Xml;
@@ -1717,14 +1718,18 @@ public static bool TryGetNativeLibraryPath(Assembly assembly, out string path)
 
                         if (SeparateLibraryDirectories)
                         {
-                            var md5 = System.Security.Cryptography.SHA1.Create();
-                            var bytes = md5.ComputeHash(s);
-                            Array.Resize(ref bytes, 16);
-                            var hash = new Guid(bytes);
-                            md5.Dispose();
+#if NET8_0_OR_GREATER
+                            var hash = SHA1.HashData(s);
+                            var guid = new Guid(hash.AsSpan(0, 16));
+#else
+                            using var sha1 = SHA1.Create();
+                            var hash = sha1.ComputeHash(s);
+                            Array.Resize(ref hash, 16);
+                            var guid = new Guid(hash);
+#endif
 
                             GetPlatformAndArch(out var platform, out var arch);
-                            dstFolder = Path.Combine(dstFolder, assembly.GetName().Name, hash.ToString(), platform, arch);
+                            dstFolder = Path.Combine(dstFolder, assembly.GetName().Name, guid.ToString(), platform, arch);
                         }
 
                         s_nativePaths[assembly] = dstFolder;

src/Demo/Scratch/Store.fs

@@ -15,12 +15,6 @@ open System.Threading
 
 #nowarn "9"
 
-let hash = SHA1.Create()
-let md5 (str : string) =
-    str |> Encoding.Unicode.GetBytes |> hash.ComputeHash |> Array.truncate 16 |> Guid
-
-
-
 module FileManagerTypes =
     let inline (++) (ptr : nativeptr<'a>) (v : 'a) = NativePtr.add ptr (int v)
     let inline (!!) (ptr : nativeptr<'a>) = NativePtr.read ptr